/Engine/Plugins/Runtime/XRBase/Source/XRBase/Public/HeadMountedDisplayFunctionLibrary.h
If the HMD has a positional sensor, this will return the game-world location of it, as well as the parameters for the bounding region of tracking. This allows an in-game representation of the legal positional tracking range. All values will be zeroed if the sensor is not available or the HMD does not support it.
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintPure, Category="Input|HeadMountedDisplay", Meta=(DeprecatedFunction, DeprecationMessage="Use new GetTrackingSensorParameters / GetNumOfTrackingSensors")) static void GetPositionalTrackingCameraParameters ( FVector & CameraOrigin, FRotator & CameraRotation, float & HFOV, float & VFOV, float & CameraDistance, float & NearPlane, float & FarPlane )